diff --git a/classes/external/external_api.php b/classes/external/external_api.php
new file mode 100644
index 00000000..cb6717ec
--- /dev/null
+++ b/classes/external/external_api.php
@@ -0,0 +1,33 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+namespace tool_dataflows\external;
+
+// Moved as part of https://tracker.moodle.org/browse/MDL-78049 so this is
+// required to redirect sites using older versions of Moodle to the previous
+// implementation.
+// Once the base supported version is 4.2, this is no longer required.
+if (class_exists(\external_api::class)) {
+    class_alias(\external_api::class, current_external_api::class);
+} else {
+    class_alias(\core_external\external_api::class, current_external_api::class);
+}
+
+/**
+ * Backwards compatibility class for underlying core's external_api
+ */
+class external_api extends current_external_api {
+}
diff --git a/classes/external/trigger_dataflow.php b/classes/external/trigger_dataflow.php
index 58a0575d..bd0562be 100644
--- a/classes/external/trigger_dataflow.php
+++ b/classes/external/trigger_dataflow.php
@@ -31,7 +31,7 @@
  * @copyright  Catalyst IT, 2023
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
-class trigger_dataflow extends \external_api {
+class trigger_dataflow extends external_api {
 
     /**
      * Returns description of method parameters
diff --git a/classes/local/step/flow_web_service.php b/classes/local/step/flow_web_service.php
index 63144d35..55312f31 100644
--- a/classes/local/step/flow_web_service.php
+++ b/classes/local/step/flow_web_service.php
@@ -16,11 +16,9 @@
 
 namespace tool_dataflows\local\step;
 
-defined('MOODLE_INTERNAL') || die();
-
 use core_user;
 use core\session\manager;
-use core_external\external_api;
+use tool_dataflows\external\external_api;
 use moodle_exception;
 use Symfony\Component\Yaml\Yaml;
 use Throwable;
diff --git a/version.php b/version.php
index fe6597ee..32e6545f 100644
--- a/version.php
+++ b/version.php
@@ -25,8 +25,8 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-$plugin->version = 2023063000;
-$plugin->release = 2023063000;
+$plugin->version = 2023063002;
+$plugin->release = 2023063002;
 $plugin->requires = 2017051500;    // Our lowest supported Moodle (3.3.0).
 $plugin->supported = [35, 401];    // Available as of Moodle 3.9.0 or later.
 // TODO $plugin->incompatible = ;  // Available as of Moodle 3.9.0 or later.